1. Field of the Invention
The invention relates to a valve device for a motor vehicle, having a housing, having a flow duct situated in the housing, having a flap which is arranged in the flow duct and which serves for closing off the flow duct, wherein the flap is fastened to a spindle, and the spindle is mounted rotatably in the housing, and having a valve seat which is arranged in the flow duct and which is in contact with the flap when the latter is in its closed position.
2. Related Art
Valve devices are used, for example, as throttle flap connectors or exhaust life gas recirculation valves, and have long been known. By making use of the rotatably mounted flap, it is possible for the flow duct to be completely closed or opened so as to realize a maximum mass throughput. Accordingly, the valve device is designed with regard to the maximum mass throughput and thus with regard to the free flow cross section in the region of the flap. With regard to the regulation of the mass throughput, the greatest difficulty lies in obtaining adequate regulation quality at minimum mass throughput, at which the flap is pivoted by only a few degrees out of the closed state. For this purpose, careful adaptation is necessary with regard to the geometry and material pairings between the flap and the flow duct. For this purpose, it is known to arrange a valve seat in the flow duct in the region of the closed position of the flap, which valve seat is correspondingly adapted to the flap and, if appropriate, to the seal arranged on the circumference of the flap. A disadvantage here is that, for different requirements that demand a different maximum throughput, respectively different valve devices with correspondingly adapted flaps and valve seats must be provided. Owing to the exact adaptation, the different valve devices involve a great amount of outlay.